A US Chinook helicopter was downed in a missile attack launched by Iraqi rebels today, killing 15 soldiers and wounding 21 others.
It was the deadliest day for American troops in the six-month-old occupation of Iraq, and the second-deadliest since the US invasion itself.
US military spokesman confirmed the casualty count but said the cause of the crash was under investigation. He said witnesses reported seeing what they believed were missile trails.
The helicopter was carrying dozens of soldiers to start leave abroad when it was struck by a missile and crashed amid cornfields.
Witnesses said they saw two missiles fired at the helicopter, which came down near the village of Hasi about six miles south of Fallujah, a centre of Sunni Muslim resistance 40 miles west of Baghdad.
American military officials have repeatedly warned that hundreds of shoulder-fired surface-to-air missiles remain unaccounted for in Iraq since the collapse of Saddam Hussein's regime in April.
The helicopter was part of a formation of two Chinooks carrying more than 50 passengers to the US base at the former Saddam International Airport, renamed Baghdad International.
Witnesses said at least a half dozen Black Hawk helicopters were covering overhead or picking up casualties.
The US command reported at least one soldier killed and 20 injured when the helicopter crashed in a cornfield near Fallujah.
Meanwhile, a bomb blast in Baghdad killed a US soldier from the 1st Armored Division today, a US army spokesman said.
The spokesman said the soldier was evacuated to hospital after the blast in the early hours of today, but died a few hours later.
In Abu Ghraib, on the western edge of Baghdad, US troops clashed with townspeople for the second time in three days, and witnesses reported casualties among both the Americans and Iraqis. There was no immediate official confirmation.
In Fallujah, Iraqis celebrated on the streets. One Iraqi said "this was a new lesson from the resistance, a lesson to the greedy aggressors. They will never be safe until they get out of our country."
The presence of the portable anti-aircraft missiles has represented a significant threat for military aircraft and raised concerns over the security of the few commercial flights in and out of Baghdad International Airport. The US-led coalition has offered rewards to Iraqis who turn them in.
It was the third helicopter known to have been brought down by Iraq's insurgents since President George W Bush declared an end to major combat in Iraq on May 1st.
A US army Blackhawk helicopter crash-landed last month in Tikrit after being hit by an unknown weapon, injuring one crew member. On June 12th, a US Army Apache attack helicopter was shot down by hostile fire in the western desert, and two crew members were rescued unhurt.
The Pentagon had announced on Friday it was expanding the home leave programme for troops in Iraq, to fly more soldiers out of the region each day and take them to more US airports. As of today, it said, the number of soldiers departing daily via a transit facility in neighbouring Kuwait would be increased to 480, from 280.
The workhorse, 10-ton Chinook, which has a crew of four, is the military's most versatile heavy-lift helicopter, used primarily for troop movements, transporting artillery and similar functions.
AP